[#125] node: Add new option WithEnvPrefix

Signed-off-by: Anton Nikiforov <an.nikiforov@yadro.com>

cmd/frostfs-node/config/config.go

@@ -45,15 +45,17 @@ type Prm struct{}
 func New(_ Prm, opts ...Option) *Config {
 	v := viper.New()
 
-	v.SetEnvPrefix(EnvPrefix)
-	v.AutomaticEnv()
-	v.SetEnvKeyReplacer(strings.NewReplacer(separator, EnvSeparator))
-
 	o := defaultOpts()
 	for i := range opts {
 		opts[i](o)
 	}
 
+	if o.envPrefix != "" {
+		v.SetEnvPrefix(o.envPrefix)
+		v.AutomaticEnv()
+		v.SetEnvKeyReplacer(strings.NewReplacer(separator, EnvSeparator))
+	}
+
 	if o.path != "" {
 		v.SetConfigFile(o.path)
 

cmd/frostfs-node/config/opts.go

@@ -3,6 +3,7 @@ package config
 type opts struct {
 	path      string
 	configDir string
+	envPrefix string
 }
 
 func defaultOpts() *opts {
@@ -27,3 +28,11 @@ func WithConfigDir(path string) Option {
 		o.configDir = path
 	}
 }
+
+// WithEnvPrefix returns an option to defines
+// a prefix that ENVIRONMENT variables will use.
+func WithEnvPrefix(envPrefix string) Option {
+	return func(o *opts) {
+		o.envPrefix = envPrefix
+	}
+}

cmd/frostfs-node/config/test/config.go

@@ -25,7 +25,7 @@ func fromEnvFile(t testing.TB, path string) *config.Config {
 
 	loadEnv(t, path) // github.com/joho/godotenv can do that as well
 
-	return config.New(p)
+	return config.New(p, config.WithEnvPrefix(config.EnvPrefix))
 }
 
 func forEachFile(paths []string, f func(*config.Config)) {
@@ -53,7 +53,7 @@ func ForEnvFileType(t testing.TB, pref string, f func(*config.Config)) {
 func EmptyConfig() *config.Config {
 	var p config.Prm
 
-	return config.New(p)
+	return config.New(p, config.WithEnvPrefix(config.EnvPrefix))
 }
 
 // loadEnv reads .env file, parses `X=Y` records and sets OS ENVs.

cmd/frostfs-node/main.go

@@ -46,7 +46,9 @@ func main() {
 		os.Exit(SuccessReturnCode)
 	}
 
-	appCfg := config.New(config.Prm{}, config.WithConfigFile(*configFile), config.WithConfigDir(*configDir))
+	appCfg := config.New(config.Prm{},
+		config.WithConfigFile(*configFile), config.WithConfigDir(*configDir),
+		config.WithEnvPrefix(config.EnvPrefix))
 
 	err := validateConfig(appCfg)
 	fatalOnErr(err)